Sexual Intercourse
Question :

If a man is not fasting due to a justifiable reason, but his wife is fasting, is he permitted to have sexual intercourse with her?

Answer :

He is not permitted to do so, and she is not permitted to allow him to have intercourse with her.

Sexual Activity
Question :

Can one engage in sexual activity with the wife while fasting, without ejaculation? Does this invalidate the fast?

Answer :

This is permissible – as long as ejaculation is not intended – and does not invalidate the fast, although it is recommended to refrain from it.