I'm gonna have to agree with my friend Krupa on that...sure people have random thoughts & any of us would be idiots to think that we are the only thought in our partner's mind. But if you are worrying about it...nine times out of ten, they are probably exhibiting some behaviour that would cause you concern...unless you're a jealous psycho where even blowing one's nose could be misconstrued as cheating. But trust or lack of it, begins with a tiny seed...love will make it grow...& doubt will surely kill it.