It can be endearing or offensive. With regard to the latter, here’s one definition from Urban Dictionary.Mommas boy is offensive? 😳. Last time I checked it was a description of one who is close with their mother, and tends to be pretty common when said male doesn’t have a father in their life.
“A male who is overly dependent on their mom into adult hood. This can lead to things such as a grown man letting his mom make decisions for him despite the fact he's old enough to make decisions for himself. He also lets his mom order him around with no disapproval. This can have a bad effect on relationships and can be the driving force to breaking up as his girlfriend can grow tired of him letting his mother control his life. This type of momma's boy tends to be looked down upon by society.”