<human>: Would really appreciate unbiased opinions from you guys.

My friend (Richard) and I have known each other for just over a year now. I'd say we're pretty close. We talk almost everyday via text, and see each other at uni at least 2 times a week. He is in a long term relationship of around 4 years, and I study with him and his girlfriend (Becca) pretty often. She's brilliant. Smart and absolutely gorgeous, the top of our class. They always talk about how much trust they have in each other, and I have never had any reason to doubt this until recently. 

Over the last two months I've noticed some slight changes in Richards behaviour towards me, which weren't there before. For instance, when we study together without Becca he will lean his arm against mine and leave it there, or rest the edge of a knee against mine. When we are standing at a bookshelf or a benchtop he will stand within 15cm of me. If we are at a desk he will brush my ankle with his foot to get my attention. The other day he jokingly pressed his palm against my abdomen to 'feel my non-existent abs'. 

At the same time though, he has been talking about Becca more and more frequently. He will mention her in all sorts of unrelated conversations, and keeps talking about how she is 'wife material', and how he's so lucky to have someone that 'fits his personality perfectly'. 

I guess my questions are:

1. I'm a pretty touchy person, but is this level of touching appropriate between friends, when one is in a relationship? Although I don't think any of it is particularly offensive, none of my other male friends do this. Should I actively move away?
2. Why would he suddenly start talking about a Becca so much? Not that I have a problem with friends discussing their SO, but it's a bit awkward when they bring them up constantly. 
3. Any idea what it means that both of these behaviours started at the same time?

Would appreciate any thoughts!

Can you condense the text into a few key points?
<bot>: Friend in a relationship suddenly gets really touchy with me. Starts talking about his GF more than usual as well. Inappropriate? Any idea about what the reason is?