Any kind of sex in an inappropriate setting. The act is referred to as dunkin donuts to avoid suspicion or simply avoid an awkward conversation altogether. The idea is that one could use "going to dunkin donuts" as an excuse or alibi, given Dunkin Donuts is often open 24-hours.
The Urban Dictionary Mug
One side has the word, one side has the definition. Microwave and dishwasher safe. Lotsa space for your liquids.
Buy the mug