I’m nowhere near having children, just playing with names
What do you think about [name_m]Theodore[/name_m] [name_m]Otto[/name_m] with an initials nickname of T.O? [name_f]Kinda[/name_f] like [name_u]Theo[/name_u] but pronounced Tee-oh. It could be any O middle, ([name_u]Owen[/name_u], [name_m]Oscar[/name_m], etc.) I thought it was really cute but do you think it could work in the real world? Or would it just get confused for [name_u]Theo[/name_u]?
I think that could work! Using initials as a nickname is definitely not unheard of. I assume the nickname is similar to [name_m]Teo[/name_m]? I think there will be some people that hear [name_u]Theo[/name_u], but the confusion should clear up quickly. Besides, the beginning sound of T.O and [name_u]Theo[/name_u] is pretty different!
I know a [name_m]Theodore[/name_m] that gets called [name_m]Teo[/name_m] 
I think it works really well! Especially with [name_m]Theodore[/name_m], I think [name_m]Teo[/name_m] pronounced ‘tee-oh’ could come naturally even without an O middle, though that is an added reason to choose it.
My only worry would be TO ‘time out’- I remember playing tag in elementary school people would yell “tee-oh!” whenever they wanted a break, and plenty of sports will abbreviate time outs to TO.
Overall, I really like the idea. It’s a great nickname choice for [name_m]Theodore[/name_m], especially with an O middle.
I think it works!!
That is super cute!!
As a Canadian, to my ear “T.O.” conjures Toronto.