I've also had a subtotal glossectomy with a free flap reconstruction. I had around 85% of my tongue removed. I have a RIG, which I think you call a G-Tube (it's similar to a PEG, but is fitted under x-ray and has a balloon to keep it from coming out.) I've also had a lot of teeth removed too.
I have nutrition shakes but am able to swallow, so I have been trying soups, smoothies, yoghurts etc to give me variety.
I've just caught up on where you are with your husband.
Here in the UK, we don't have the swallow test until after radiotherapy and that's of the speech therapist thinks its required. It's because it puts more stress on the patient when they're trying to recover. It's a last resort thing. The speech and language team (SALT) teach patients how to swallow and talk, which will be the same for you.
The back flow into the tube is totally normal. I too had a little "oh my gosh" moment when I saw it, but I spoke to my nurse who said it's OK. Liquid will enter all avenues and this is just another avenue for it to go in.
I love that you're making smoothies and shakes for you husband. That's really helpful. I find there are some days where I'm just too tired, or my mouth is sore and I don't want to take things orally, so that's when I use my tube more (I currently use it for medication that I can't swallow and for a protein drink that tastes disgusting, so I'm happy to bypass my mouth on that one
) As your husband is going through radiatotherapy, he just might not be in the mental state to want to swallow nutrition. Yes he needs to keep up with his swallowing throughout the day, but even dry swallowing will help.
I've not started my radiotherapy and chemo yet, I get that joy next week. I have 33 radiotherapy sessions and 3 chemo ( 10 hours long, so overnight in hospital for each session) plus I'm having immunotherapy as I'm part of a clinical trial. These will all make me feel very tired, plus whatever other side effects I'm going to have.
I've told my husband that if I'm too tired to physically take nutrition orally, then he is allowed to take over and put my nutrition through my RIG. He must encourage me to sip water as it'll ease any sores in my mouth and also keep up with my swallow, but he shouldn't push it as I know I will get defensive.
So it might be worth chatting to your husband an dasking him if he's just too tired to take nutrition orally. If that's the case, ask him how you can help him.Things might have changed for him of what he wants and he just doesn't want to ask or burden you.
I hope this helps you and your husband.