My jeans too tight cant squeeze in too 501s?

this morning i try button up last button on my favourite pair of indigo 501s . didnt think i gain weight i stood up tummy love handles pour over tight 36 30 indigo 501s top button came tight try walking in them look in mirror notice i now have go a buy next size up 38 doubt lose weight fit comfortable in 36 levis 501 use too be 34 waist never got back into them dark blue 501s have too go buy new pair