TL;DR: Mom won't enforce physical custody schedule with my tween/teenage kids. I want us to stick to a schedule- she wants them to come back-and-forth at-will, which will always mean to her house during my time. I think she is doing this to get full custody... I don't know what to do!!

Dad here- 2 kids, married 15 years, separated for a year or so. New custody order from the judge (settled out of court) state 50/50% physical custody. It is VERY hard to get full-time custody where I live, and I think if she thought she would get it, she would have taken me to court. We have a very contentious relationship and co-parenting is not existent.

The kids are older now (tween and 16-yr old)and she seemingly wants to manipulate the children and "win them over" to her place so that she can get them full-time. She has overtly made me look bad to them (with direct and very personal statements about me, and more subtly by never supporting me in any decision/accountability/punishment), never makes the kids do anything difficult (chores, live up to commitments, etc.), lets them skip school all the time, spoils them non-stop, and with her constant coddling, by now, the kids just never want to come over to my place. Mom's house is the fun and accountability zone, perfect for teenagers!!!

Add to this, our tween has a lot of anxiety about going to school and, well, a lot of things, and is at a difficult age. We get along REALLY well- many common interests, and I am very hands-on dad that has always been there since both kids were infants- spending as much time or more with the kids through the years (especially in phases where my ex was having an affair) but I think his mother and him are basically co-dependent. He wants to spend as little time as possible with me, and pretty much every day before our transition, he calls me, crying, freaking out, and asking me if he can stay with mom (longer)- for a week, a day- it doesn't matter.

She has a policy that the kids know by now: "you can always stay with me"- which is my policy too (but the parents need to be 100% in agreement first) but absolutely never tells him that he is just going to have suck it up and to go over to dad's house. If she does, she must tell him that "we are doing this because dad says so" and I've even seen my son say that "mom better not get in legal trouble", and even validate that he shouldn't have to go, because I am the only one he ever seems to need to convince that this needs to happen...

He is at the point where he is getting very angry and rebellious about this, hearing from his mother that he can just go over there any time, and hearing from me that we must stick to the schedule. At one point my son about 5 months ago was leaving around bed time (sometimes with no shoes) to walk to my house (we live about 0.25 miles away from each other).

Ex-wife basically just tells my son that "you can ask your dad" and has him call me- she won't talk to me about this most of the time. She doesn't support me or set boundaries with my son. I tell my son "me and mom need to talk about this"- but she has already set me up as the "bad guy", and she has already set the expectation that "you can always stay with me".

I am getting at the point where I am trying to "entice him over" with video games and fun things, just to have him. I've already re-done his room, bought him a gaming computer (was combo Christmas/birthday gift) always try to make our first day together fun as hell, really backed off of chores... I take him to therapy (my ex undermines that as well) and recently started seeing the therapist with him...

I feel like I am in a competition with my ex and we are trying to "win-over" our kids. It is just so damaging to them. I also don't want to just give him my custody with them. I am a very good (IMHO) father, very close to them, and I think kids need both of their parents in their life as much as possible (which is in agreement with the courts in my area).

Can anyone give me some advice here? I am so beat-down by this....