Guys and STDs

Fay • I`m a Scorpio. <3 I love knowledge, sex and everything that comes in between.
Every time I tell one of my sex partners I get STD checked often they get all offended, and tell me they know they're clean and they've been checked. Is it more common for guys to care about that kind of thing than I thought? Because I always thought they didn't care as much. Or is it because they don't vocalize their concerns as freely?