right or wrong?

I have a fiancee' who is involved with his kids..:)...the ex has asked him to do some chores around the house due to some unforseen circumstances with her soon to be exhusband, which involves the kids.....my fiancee' went and did some fixer upper stuff and then the ex childrens mom asked him to stay for BQ and he did...........I politley voiced my opinion that this was not right to do and was accused of being jealous and perinoid, and thats wat broke up his relationship with this ex...I used my ex as example in the same senerio and he had no comment but to say that his situation is different.....please give me your thoughts and opinions......