My Boyfriend Can Sometimes Be Very Jealous

So my cousin that last year some things happened with (see my other stories) is coming for a visit and since last year we did kiss and i did very much like him my boyfriend is not very happy he will be staying in my house for 2 weeks. He says "oh yea i trust you i just don't trust him i'm a guy i know how they are," but i can't get him to understand that my parents know about last year and will be keeping a very close eye on us and he has a girlfriend and most importantly i would never do that to him i love him too much and it takes 2 for something like that to happen. by the way i definitely understand why he would be jealous it just kinda sucks because i don't want him to have to feel that way.