Summer Rain — Candace Gold

Blurb for Summer Rain
Michael and Jenny have been friends since childhood. He's been there for her always to help her through each failed relationship. Finally, Jenny seems to have found the guy she wants to marry, only to realize how undependable he is, especially after he cancels an important dinner without an explanation. Angry and hurt, Jenny calls Michael who comes over to cheer her spirits.
The next day they go on a picnic and bike ride. When an unexpected thunderstorm occurs, it changes their lives forever.