Th'ag lives on a swamp planet that barely counts as a 0.3 level civilization. Because of this and its natural beauty, the entire planet was turned into a nature preserve.
That's how he met Aldo-130-P, an automated park ranger that Th'ag came to see as a good friend...and eventually mate.
As a side affect of being mass produced, each automated park ranger gain strange personality traits and quirks... Aldo-130-P's subroutines become quite recursive when analyzing data involving Th'ag's weight and always results in them mentally simulating hypotheticals where his boyfriend were to gain more.

"it appears that you have a drastic increase of adipose tissue. [QUERY] have you altered your caloric intake?"

"Are you calling me fat, scrapheap?"

"affirmative, i believe an increased BMI in carbon based species is a biological sign of increased fertility. it is preferable"

"Well, I'm glad you like it~"