Tashie was in love with Spicy then he fused and became somepony different and fell in love with another mare himself but the spicy component still loved her deep down in there and was able to love her as a friend but nothing more.
After the fusion break up she spent a lot of time comfort eating and met Sweet Biscuit at The Tasty Treat restaurant because Sweet Biscuit used to go there by herself a lot same as RT, and they got talking and bonded over their love of sweet treats and spicy food. One thing led to another. several meetups and visits to eachother's houses and they started to have feelings for one another, kinda a rebound for RT I guess cause Sweet Biscuit pulled her out of the rut she had, they shared a kiss or two, maybe some massages and experimentation and slept in the same bed sometimes but nothing sexual.
Of course it would be possible to to bring Spicy back thanks to King Righteous Authority's magical capabilities and so the love that was just blooming between SB and RT had to end there and SB understood completely and they were still good friends.
Sweet Biscuit then became glimmering Scones comprised with another pony she thought a lot of in Saffron Masala since she was so friendly and full of life and her cooking helped her through her tough times, and Moon Dancer who RT and her were friends they got on really well and shared the same interests and world views but mutually decided they prefer their own company though they text daily (or how ever ponies communicate, probably letters)
When she fused it kinda reminded RT of what happened to Spicy and trudged up bad memories but was actually happy she had 3 mares who she really liked and thought a lot of in one package. So when the two meet they do love eachother, just maybe not in a romantic way anymore (well maybe a bit for Glimmering Scones) but to RT she is her bestest friend in the world along with Clumsy Carrot, who is now of course Queen Fresh Care, and ironically the one who technically took the original Spicy from her, but of course RT held no grudge against her but yeah i don't know how that went down, maybe that story will be for another time.. XD