What movie has a Grouch Marx character, who suggests a 3some with his wife

Hi there, its a comedy I think, and it has a grouch marx character (thick moustance and glasses), and hes married to a woman, and (i think), he walks in with her and her lover, and suggests a 3some.

Hubby (Marx guy), actually says you take the top, and I'll take the bottom, then we'll swop around on her?

Do you guys and gals know?

K

Oh one more thing. He comes out of a pool I think, in snorkels and goggles, and walks about with them.

Any takers????