I never made DS "socialise", no matter who wanted cuddles. He cries, he's back to me NOW. Annoyed everyone for the first year! Now he loves playing with people he's introduced to individually. A big social event and he wants people he knows - even if he only sees them 3-4 times a year, like my sister (he adores her). He'll play with my sister within 5 seconds of seeing her for the first time in months, but in a big "party" situation he doesn't want to meet new people without someone safe there.

I think that's very healthy and that DH is exactly the same - stays with people he knows or clings to me because he doesn't know all my cousins yet. (To be fair, I struggle with cousin's cousins or my dad's cousin's children or my grandma's cousin's children and grandchildren a bit too.) Would you like it if you met a new branch of the family and your only safe point deserted you?