Hate to say it but if he is basing this decision on what his mother wants then he is not a "man".
I love my mother dearly and I am grateful to her and my dad. However, he is of the age of majority and has a family of his own. A "man" would put his and his own family's interests first. He makes enough money to provide financial stability for his mother, should she require it.
Would we have beaten the Germans twice in war if every British, American, et al young man old enough to make his own decisions had to ask his mother if he could join the army?
My 2p, though it is likely worth less than that.