Your glute muscles are like 13 year olds lying on the couch - the longer you avoid disciplining them and MAKING them work, the flabbier and lazier they'll get. And they won't support you - ever.
Here are the reasons WHY you need and want strong butt muscles:

Great Glutes

protect your back and spine
balance out the over-used front of your legs (quads)
protect and stabilise your hips and pelvis
they look great in shorts
they look great in everything

Here's a few moves you can do TODAY:

Deadlift Dumbbell

1. Deadlift with Dumbbell - maintain a long, straight spine as you lower the dumbbells straight down - only lower as far as you can maintain a straight back and raise SQUEEZING YOUR BUTT

Glute Bridge

2. Glute Bridge: Squeeze butt to raise hips and lower - lower with CONTROL! Don't just drop. Raise, squeeze, hold, lower. Repeat.

Single Leg Deadlift

3. Single Leg Deadlift - go for light weights or NO weights. Maintain a long, straight back as you lower the weights and extend one leg back parallel to the floor. As you rise, bring the leg back in (advanced: don't touch down). Repeat.

4. Go to BodyPump, Pilates, Dance, but whatever you do, FOCUS ON SQUEEZING and USING your glute muscles because they are lazy unless you make them work.