Ricky doesn't have the right to dictate when Lucy takes showers. On the flip side, Lucy doesn't have the right to dictate when Ricky will "be close" with her and when he's willing to share a bed. I think Lucy should continue to follow the hygiene practices that work for her, and Ricky should adjust his own behavior to accommodate his eccentricities. As PPs have said, Ricky is the one outside of societal norms and Lucy has already made accommodations for him, so it's his turn to be flexible.
So, Lucy can go 36 hours between showers if she likes, while Ricky can set up his own separate bed to sleep in it on those occasions. If Lucy wants to share a bed with Ricky or otherwise "be close", she should make the effort to shower beforehand so he's comfortable with it. If Ricky wants to share a bed/be close with Lucy, he should either put up with her current state of cleanliness or ask her if she would take an extra shower as a favor to him. If either of them is unhappy with sleeping apart or not being close but is unwilling to be the one to compromise, then it may be time to rethink the relationship.
IMO, Ricky should also be the one responsible for the extra work involved in accommodating his hygiene preferences, e.g., the frequent changing and laundering of the sheets (and probably his towels, and his clothes, etc., since he showers so often), since he's the one who's pickier about it. Or they could share the work for a set sheet-laundering schedule they both find appropriate, and Ricky could handle all extra laundry beyond that resulting from his pickiness.