I didn't think the weather-forecast is as bad as that - anyway it certainly won't rain the whole weekend (next week I'm hiding away if it did!

)
You don't say where your boy-friends parents live!?! Might they be interested in the real Swiss
folklore festival in Wädenswil on Sunday. Zürcher National costumes, dancing (the national-costume variety, plus Line-Dancing and a steel band too). Handwork, food...
If it poured at least you would have the satisfaction of seeing everyone else getting wet too.