This vacation is stressing me out. My husband and I do almost everything together and I follow him around where ever he goes. He was hurt when I told to do this trip without me. The only time we really argue is when I bring up the "Chris situation". Which I don't now. But because I can't get any resolution it's on my mind all the time. Which means Chris is on my mind all the time. I think up scenarios where he comes onto me, what should I do in such a situation, and should I scream, I should I slap him, should I give him a stern talking to...on and on I go. I think by the summer I would have aged ten years.
I just wished my husband would believe me and at least protect me from it. From Chris. He is always so hands on with me and in this case he has left me out in the cold it feels like.
Are you frequently beset by obsessive thoughts in other areas of your life? I ask because the bold above seems rather...intense...given the facts of the situation you've relayed here. It feels like an out of proportion reaction to what even you admit is a situation you aren't 100% sure of. It seems like you may be obsessing over possibilities - ones that may or may not actually be possible. If these types of intrusive thoughts are a problem for you in other, non-Chris-related, areas of you life it may be a symptom of mild (or not) OCD, or perhaps of some type of generalized anxiety issue.
Otherwise, there seem to be a few things that spring to mind:
One, you're allowing this situation to occupy way too much of your brain space. You need to find ways to occupy your thoughts that aren't related to this. You can control your thoughts. So when you find yourself ruminating over Chris, re-direct your thoughts to other things. If you're disciplined and consistent, it should get easier to not think so obsessively about this situation.
Two, you seem to really be pushing for Chris to be hitting on you and for this situation to be a real problem. Your husband and best friend don't seem to see the situation as you do. I'm sure Chris is probably flirting, but that doesn't have to be a huge deal. Shut him down. You have that power. Don't respond to innuendos, don't spend time alone with him, have strong boundaries of your own. He'll either get the hint and stop, or this is just his personality and he'll keep it up but won't escalate. Because you will not let him escalate. Making a huge deal about a man hitting on you, when even you aren't really sure that he is, and he's not actually done or said anything inappropriate, sort of feels like you're drama-shopping.
Three, how is your marriage otherwise? Are you getting as much attention and emotional connection from your husband as you'd like? How's your self-esteem? You seem very insistent that your husband do something to "save" you from Chris's (maybe) advances. Some women feel the need to be regarded as the fair damsel, while they need their partner to play knight in shining armor for them, in a sort of fairy-tale drama. Might this be what's going on? Because the truth is that you don't
need your husband to save you from this. There's really no dragon here. Your husband isn't required to be your white knight. You aren't a helpless damsel, and you can take care of yourself, particularly with the "threat" is something so benign as a friend of your husband's who may or may not actually be hitting on you.