The quarantine rules in my country began to lift off, so gyms opened again, which is great because me and my LTR got slightly lazzier during it, and she asked if she could train with me. I accepted. Now, I know what you are going to say "Cry, she's clearly trying to set hypergamy into play and branch swing". Possibly true.

My main concern is not with her (even though she's a part of the problem) but with a guy that goes there as well. Before me and him used to go along well, but after the gyms opened up (2w ago) he's been disrespectful. I know it's normal for a decently atractive girl to get attention in the gym and he's built, but he's been acting either thirsty or too interested in front of me. Either way he's being disrespectful.

-he knows we're dating

-Every time he can he's around her (she literally works out with me so I know), one time he even wasted 10/15m of his 1h session just to be close to us, just staring at his phone and then her before deciding to do his exercise.

-Eye contact. That's something mutual between them. They either look at each other when the other's not watching or they keep some eye contact with each other, regularly intercalating and when they think I'm not noticing. Either way she's not denying the attention he gives her which will have to be dealt on it's own.

But I'm not quite sure how to deal with the guy (and her too tbh other than becoming distant myself). We used to talk occasionally, but I feel he's starting to step up his boundaries. Usually I just act like he's not in there, or I just laugh after seeing how focus he is on her (like a hyena trying to get the last piece of meat of the animal's carcass), and obviously I'm not going to mateguard but I don't know any concrete way to deal with this besides ignoring or laughing it off, so I thought I'd get your thoughts on it.