0h love the topic ..
he has been expressing in his own sublime way from the very beginning. here are the ones i can recall. ALthough i bet there were many more may be subtle ones as mr. SUBTLE he is !

in ( early bbm tent days)
1. soup favour

2. sharing his thoughts with jack - talking to him - for somebody like ennis that was "some" move boy !
3. SNIT !!!

4. the hug from back (this was shown at the end though)

after that
1. his breaking down while leaving ( however this would not come under "expressing" because thats a self-sulk )
2. you bet reply
3. KISS !!! after 5 years - now this was his most expressive uncharacteristic outrageous burst

4. motel scene ya
5. harmonica
6. and of course the final confrontation