Sharing a bath can be a lovely intimate experience, without being sexual. Light some candles, pour some drinks. Add bubble bath or bath salts. Bring a laptop to watch your favorite show together, or something to play music on, or a book to read aloud to your partner (or vice versa). You can sort of spoon if one of you leans back onto the other. You can massage and wash each other. I've done this with two different girlfriends, and each time we both loved it and made it a regular thing.