How can I hear myself w/o delay?

[Boudoir Guitar]

If he's ALSO direct monitoring (which he should be at this point), it IS kind of annoying...

 

[Sascha Franck]

If he’s monitoring vocals…even the slightest latency is an issue

Depends on a whole lot of factors.
In some cases, it's even that higher latency might fix the issue, simply because the delay between what you hear through your skull and your headphones is shifting from nasty phasing to more pleasant doubling.
Also, if it was a general issue, pretty much no singer could work with IEMs live. I mean, pretty much all consoles are digital these days, so there's at least some latency involved. Add to this that I was working with plenty of singers in a production using a first generation Aviom monitoring system, introducing around 5+ms (IIRC) on its own already. There's never been much complaints. An easy trick pretty often is to add some room FX just for the monitoring path.

 

[Sascha Franck]

If I’m correct my daw runs at 5 Ms…and I wouldn’t offer that as a monitor mix ever. But..maybe what the settings say doesn’t add up to the actual latency..never measured it.

5ms should be absolutely fine in terms of timing, even some discriminating folks should have rather little issues with that (after all, 5ms equal less than 2 meters of sound travel), so in general, all you need to do is to take care that things don't add up - which they sometimes unfortunately do. Just to name these:
- Digital consoles of unknown variety, and even more so, unknown operators ("noonoo, I promise, there's no FX on your monitoring path" - and I was detecting a (lookahead?) limiter after the show...)
- DSP controlled monitors.
- Digital wireless systems.

Still, you can usually get along with all these (fwiw, that's why I always try to bring my own wedge or little analog mixer on IEM jobs, so my own signal is 100% as I know and want it).
Singers usually can get away with, too. After all, their "instrument" isn't exactly transient-heavy and it's also not that the average singer would be an in-the-pocket-timing-monster. But then there's the "phasing-through-skull" effect, which can be quite nerve-wrecking to deal with, especially in case you need to set up your singer's monitoring scenario.

 

[Sascha Franck]

For guitar playing I’m fine with 5 Ms..

For singers in a recording session , at least the ones I record..the phasing is not acceptable, and I totally agree…
I mean…you could get by with it, survive the session…but that’s not what recording should be about imo.
Again, not 100% where the threshold lies…but phase issues happen fast

I absolutely agree with you. However, next time, try to trick them out and raise the latency (somewhat over 10ms). Seriously, give it a testrun!

And fwiw, forgot to say this: Personally, I'm also monitoring externally. Even for my guitar stuff as these days I prefer to use sounds out of whatever hardware I have available (typically a mixture of analog pedals and one of my modelers), but the room FX for monitoring pleasure are coming out of the DAW. Depending on which DAW it is, things might be different, but in Logic I'm feeding an input channel with the FX send of my monitoring mixer, the input channel isn't running into any output but only feeding my 100% wet FX busses (and some 6ms of latency really don't harm on delays and reverbs). I'm doing it like that since over 2 decades by now, works absolutely well. Obviously, this also works for vocals.

 

[Sascha Franck]

You obviously never worked with my girlfriend

Very likely that's correct.