Vint70s-Lvr: This flick brings together Glenn Steers, Tom LeDuc and Jimmy Metz, three of the hottest daddies of pre-condom porn. Jimmy is working up on a roof. He spies Tom and Glenn making out on the hot tub deck below, and joins them for a suck and fuck. This video is not commercially available for streaming, but you may still find a tube site that hosts it.
Sources: Tumblr, VHS archives.