Is this a permanant arrangement between the ex and his mother or does she need a place to stay? If she doesn't have to stay there then I feel that it definately is wrong on his mothers behalf but if she needs some where to go and has no where else..then I can understand his mother. Of course jealously does play apart, but why shouldn't it? You have every right to feel that way!!! My suggestion is talk to his mother or have him talk to her and find out what the deal is. If he has no plans on getting back with his ex...then he needs to tell her that what she is doing is wrong and that she should move on...good luck :):) could you respond to dreamer75??? boyfriend/church...thats me :)