Are you sure that's how THEY feel or is it your perception only? Often what we think someone else is thinking is not what they are really thinking at all.
Maybe you're one of those people that won't stfu about their sig other?
I think that might be a simple crush ...Shall we proceed?
maybe u pay more attention to ur bf/gf than u do them..
Lots of people steer clear or try to give you space when you're in a relationship. It's pretty common.