Well, can you recommend any ointment for long lasting intercorse?

No !: What comes to my mind is the use of topical anaesthetic creams, but it might not provide what is asked for; besides, it might abolish all kind of sensations during the act for the couple and not only for the one using it, as it spreads to the skin and mucus membranes of the genital tracts. Condoms might give longer duration of intercourse as it reduces the sensation to certain extent.

Well : Plain Vaseline or KY jelly