The mark of Srivatsa adorns the chest of Lord Visnu, and therefore when Lord Visnu embraced Lord Siva while being circumambulated, the Srivatsa mark touched Lord Siva's bosom
Expressions researched:
"The mark of Srivatsa adorns the chest of Lord Visnu, and therefore when Lord Visnu embraced Lord Siva while being circumambulated, the Srivatsa mark touched Lord Siva's bosom"
Srimad-Bhagavatam
SB Canto 8
Śukadeva Gosvāmī said: O King, having thus been praised by the Supreme Personality, who bears the mark of Śrīvatsa on His chest, Lord Śiva circumambulated Him. Then, after taking permission from Him, Lord Śiva returned to his abode, Kailāsa, along with his associates.
Śrīla Viśvanātha Cakravartī Ṭhākura remarks that when Lord Śiva was offering obeisances unto Lord Viṣṇu, Lord Viṣṇu arose and embraced him. Therefore the word śrīvatsāṅkena is used here. The mark of Śrīvatsa adorns the chest of Lord Viṣṇu, and therefore when Lord Viṣṇu embraced Lord Śiva while being circumambulated, the Śrīvatsa mark touched Lord Śiva's bosom.