When your mom starts dating
If you're dating a guy like this, I recommend you cut your losses fast unless he gets help or becomes proactive about growing up.Otherwise, he may never let go of mom, or worse yet, he'll turn you into his mom and expect the same from you.
If he's worried that dating will cut into your time together, for example, then you might create some special one-on-one time with him.
In general, the younger your guy, the more slack you can cut him when it comes to cutting the cord.
As long as he's at least taking baby steps as he gets older, the less time and energy you should spend worrying if it will ever happen -- it will, it just may take a little time.
For instance, say to him, "How about if we join her for Chinese one Sunday per month as opposed to every one?
" Regardless of how many boundary-setting suggestions you offer, he has to be willing to give her the message.