Our expert says:
There are no established rules about such things, especially as so much depends on the individuals and the history of the relationship.
Have you noticed how most fights are actually abou something rather silly ? You don't reveal the time-scale here, but it sounds like a rather recent tiff, and he is indeed probably still sulking.
Might be best to give him a couple of weeks to cool off ( or warm up ) and then make a simple, friendly, calm, approach, saying you're sorry he was apparently so hurt by a silly row over something so accidental and unintended. You can say you have really missed him, and would be happy to resume the friendship, but that you respect his feeling, and leave it to him.
A humorous card is dodgy, as it can be easily misinterpreted. Especially by such a solemn person without a sense of humour. Maybe send your warm good wishes to the cats ?
The information provided does not constitute a diagnosis of your condition. You should consult a medical practitioner or other appropriate health care professional for a physical exmanication, diagnosis and formal
advice. Health24 and the expert accept no responsibility or liability for any damage or personal harm you may suffer resulting from making use of this content.