The bet is not the problem ooh. It's the small losses that becomes big one. That's one aspect I expect someone not to neglect. That's why having a maximum is crucial even though you are playing for fun. At a point, you have to stop. Isn't it? Yes. Apply your appropriate risk management. Honestly, bothering yourself with all these house edge and stuff will hurt you. That's why the fun has to be there. It's still ok as you are questioning it. That's very ok. You can still do this calculations and still get your fair share of disappointment.
Some will tell you that they are playing for fun which is the reason why they also bet on the sides, I don't understand i really understand the different feelings they derives from the very strategic game pattern that even sets them more at risk.
Meanwhile after loosing the bet they are still the ones complaining that if they never included the side bets in their game and just played straight games they would had win.
It is also quite funny how we are just forcing ourselves to describe our gambling activities as fun when we are focused on the profits but finds the casinos or sportbooks unfair when slight decisions we makes especially in the side bets turns to be the barrier that ruins our winning.