Ojisan Love Hame Wagon

Eikichi Oonuma, a middle-aged doctor who runs a small clinic, is suddenly confessed to by a big, blond-haired delinquent and forced into a van. The man turns out to be Shinya, a deliquent Eikichi saved before. Shinya hugs him, kisses him, and in no time at all, they're living together!

(Source: Takeshobo, translated)