Why else would she parade around the gym with her massive cock hanging out for all to see? When she gets it fully hard from lifting heavy, her big dick can be a bit unwieldy for Lisa to handle on her own, so she asks around for a spotter – someone who can hold her cock out of the way while she lifts, so it doesn't get in the way of a good workout. If she approached you like this, cock out, rock hard, and asked you sweetly for a hand, could you really say no?