it is capable for a 10 year old, he is matured enough to know what was good for him/her
There are anime's that are for kids, there are also anime's that are for grown ups.
Depends on the mind of the 10 year old. If the 10 year old knows what are the right or wrongs, then I think you can definitely watch a bit of the matured anime's. If not then you can watch at least family-friendly anime's.
Even though I'm a grown up, HAIKYUU IS STILL MY FAVORITE ANIME. Just do what you want. If you want to watch anime, sure go watch it. "But don't go too deep or you'll be drowned." ;)
disloyal to your partner it makes the relationship to have no trust each other. and maybe it can cause of misunderstanding to each other and until it can break their relationship. and also it is a sin. because god said that we must be loyal and be trusted to our partner. because a loyal relationship to each other has a good relationship to the partners. so reminder to the couples in there be loyal to your partners.