So, I've made it a habit to get the most out of my girlfriend. It's an LTR that's coming up on 2 years.

I understand that she could be getting comfortable. She knows me intimately, so she can find room to wiggle. I get all that.

But, she's pushing back on the physical stuff. Now, admittedly, if I took the time to describe some of these activities in detail, [I'd seem] pretty sexually immature. Full disclosure: I didn't have sex until 22 (strongly correlated with my switch from Christianity to agnosticism).

I grab on her daily. She has told me how much she likes my hands on her, but recently she has verbalized that she doesn't like certain things. However, this reminds me of how things started going south with my ex wife. She eventually dismissed every form of physical affection I had for her.

Now, I'll spare you the details for obvious reasons, and yes they involve all of my and her body parts.

She just started her period and does that matter (I think it might), or are her verbal boundaries reasonable and understandable now that she believes we are in a permanent committed relationship (we're not)?

If I am being sexually immature (my words, not hers), how do I improve my fun time with her?

Edits in brackets.