you're probably just more relaxed and outgoing, and because of the subconscious body language you emit by not worrying about being on the pull, guys pick up on it and feel more attracted to you.
being in a relationship or levels of attention may not matter to your mates when you're out having a good time with friends, so unless they point out what you posted i wouldn't worry about it.
if you find it a problem don't make eye contact or look around at other guys, or if you are at more of a social event where you're talking to new guys just chill out and see what happens. talk to them normally like a friend. they may not be as interest in a sexual way, just you're a fun person to talk to.